U.S. patent number 11,364,465 [Application Number 16/605,905] was granted by the patent office on 2022-06-21 for building, and method for controlling gas molecule concentration in living and/or activity space in building.
This patent grant is currently assigned to C'STEC CORPORATION, HIEI KENSETSU CORPORATION, ISHIBASHI KENCHIKU JIMUSHO CORPORATION, KINDAI SETSUBI SEKKEI JIMUSHO CORPORATION. The grantee listed for this patent is C'STEC CORPORATION, HIEI KENSETSU CORPORATION, ISHIBASHI KENCHIKU JIMUSHO CORPORATION, KINDAI SETSUBI SEKKEI JIMUSHO CORPORATION. Invention is credited to Tsukio Eto, Akira Ishibashi, Junji Matsuda, Nobutoshi Noguchi.
United States Patent |
11,364,465 |
Ishibashi , et al. |
June 21, 2022 |
Building, and method for controlling gas molecule concentration in
living and/or activity space in building
Abstract
A room 100 in a building has a living etc. space 101 of volume V
that is an enclosed space. Ventilation of an air flow F is
performed from the outside to the living etc. space 101.
Entering/exiting of air as an air current between the inside of the
living etc. space 101 and the outside is eliminated, and at least a
part of the boundary between the living etc. space 101 and the
outside is configured from a gas exchange membrane 310 having a
diffusion constant D, a thickness L, and an area A for gas
molecules of interest. When air inside the living etc. space 101 is
sufficiently agitated and the concentration of gas molecules
constituting the air is made spatially uniform, .eta.(t) is
controlled so as to vary according to
.eta..function..eta..times..function..times..times..times..times..times.
##EQU00001## B(m.sup.3/s) is the gas consumption amount inside the
living etc. space 101, .eta..sub.1 (t) is the gas concentration
inside the living etc. space 101 at time t, and .eta.0 is the gas
concentration of the outside.
Inventors: |
Ishibashi; Akira (Hokkaido,
JP), Eto; Tsukio (Saga, JP), Noguchi;
Nobutoshi (Saga, JP), Matsuda; Junji (Hokkaido,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
C'STEC CORPORATION
HIEI KENSETSU CORPORATION
ISHIBASHI KENCHIKU JIMUSHO CORPORATION
KINDAI SETSUBI SEKKEI JIMUSHO CORPORATION |
Hokkaido
Hokkaido
Saga
Saga |
N/A
N/A
N/A
N/A |
JP
JP
JP
JP |
|
|
Assignee: |
C'STEC CORPORATION (Sapporo,
JP)
HIEI KENSETSU CORPORATION (Hokkaido, JP)
ISHIBASHI KENCHIKU JIMUSHO CORPORATION (Saga, JP)
KINDAI SETSUBI SEKKEI JIMUSHO CORPORATION (Saga,
JP)
|
Family
ID: |
1000006383360 |
Appl.
No.: |
16/605,905 |
Filed: |
March 23, 2018 |
PCT
Filed: |
March 23, 2018 |
PCT No.: |
PCT/JP2018/011601 |
371(c)(1),(2),(4) Date: |
October 17, 2019 |
PCT
Pub. No.: |
WO2018/193789 |
PCT
Pub. Date: |
October 25, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200171427 A1 |
Jun 4, 2020 |
|
Foreign Application Priority Data
|
|
|
|
|
Apr 17, 2017 [JP] |
|
|
JP2017-081064 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F
7/007 (20130101); B01D 46/521 (20130101); B01D
53/229 (20130101); B01D 2053/221 (20130101); B01D
2279/50 (20130101) |
Current International
Class: |
B01D
53/22 (20060101); F24F 3/167 (20210101); F24F
7/00 (20210101); B01D 46/52 (20060101); F24F
7/007 (20060101) |
Field of
Search: |
;55/385.2 ;454/187
;128/200.11 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2014109432 |
|
Jun 2014 |
|
JP |
|
2015111035 |
|
Jun 2015 |
|
JP |
|
2015111042 |
|
Jun 2015 |
|
JP |
|
2018071795 |
|
May 2018 |
|
JP |
|
Other References
International Search Report for Application No. PCT/JP2018/011601,
dated Jun. 26, 2018. cited by applicant.
|
Primary Examiner: Pham; Minh Chau T
Attorney, Agent or Firm: K&L Gates LLP
Claims
The invention claimed is:
1. A building comprising: at least one room, the room having inside
a living and/or activity space that is an enclosed space, if
performing ventilation of an air flow F from the outside to the
living and/or activity space, assuming that the volume of the
living and/or activity space is denoted as V, the gas consumption
amount inside the living and/or activity space is denoted as
B(m.sup.3/s), the gas concentration inside the living and/or
activity space at time t is denoted as .eta.(t), and the gas
concentration of the outside is denoted as .eta.0, .eta.(t) being
given as follows when air inside the living and/or activity space
is sufficiently agitated and the concentration of respective gas
molecules constituting the air is made spatially uniform:
.eta..function..eta..times..function..times..times. ##EQU00025##
eliminating entering/exiting of air as an air current between the
inside of the living and/or activity space and the outside, and at
least a part of the boundary between the living and/or activity
space and the outside being configured from a membrane not passing
through dust particles but passing through gas molecules having a
diffusion constant D, a thickness L, and an area A for gas
molecules of interest, .eta.(t) being controlled so as to vary
according to the following formula when air inside the living
and/or activity space is sufficiently agitated and the
concentration of respective gas molecules constituting the air is
made spatially uniform:
.eta..function..eta..times..function..times..times..times..times..times.
##EQU00026## further the area A of the membrane being set so as to
satisfy A.gtoreq.FL/D between F and the area A of the membrane
where F is ventilation air flow required by law or other reasons,
wherein the building further includes at least one gas exchange
device, the gas exchange device having a box-like structure
constituting an enclosed space with at least two gas absorption
openings and at least two gas exhaustion openings, one of the at
least two gas absorption openings communicating with one of the at
least two gas exhaustion openings and the other one of the at least
two gas absorption openings communicating with the other one of the
at least two gas exhaustion openings, the two communicating paths
being configured so that while they form independent paths
respectively, they lies adjacent each other and they are separated
by the membrane not passing through dust particles but passing
through gas molecules, air introduced from the outside space
surrounding the room being introduced into the box-like structure
of the gas exchange device from one of the gas absorption openings
and sent out to the outside space from the gas blow opening
communicating with the gas absorption opening, while air inside the
living and/or activity space being introduced into the box-like
structure of the gas exchange device from the other one of the gas
absorption openings and returned to the living and/or activity
space from the gas exhaustion opening communicating with the gas
absorption opening, the membrane having the area A' set by scaling
of {(V/A')/(D'/L)} where V is the volume of the living and/or
activity space, A' is the area of the membrane, L is the thickness
of the membrane, and D' is the diffusion constant of carbon dioxide
in the membrane, the area A' of the membrane being set so as to
satisfy '>'.times..xi..xi..times.'.times. ##EQU00027## where B
is the carbon dioxide generation rate inside the living and/or
activity space, .xi.0 is the carbon dioxide concentration in
equilibrium state with the outside when no carbon dioxide is
generated in the living and/or activity space, and
.xi.(.xi..ltoreq.5000 ppm) is the target carbon dioxide
concentration inside the living and/or activity space.
2. The building according to claim 1 wherein a wall-mounted air
conditioner is installed on the wall of the living and/or activity
space, a prefilter using a medium performance filter is attached to
an absorption opening of the top of the air conditioner, and all of
gases flowing inside the living and/or activity space from a blow
opening of the air conditioner is returned to the absorption
opening of the prefilter.
3. A building comprising: at least one room, the room having inside
a living and/or activity space that is an enclosed space, if
performing ventilation of an air flow F from the outside to the
living and/or activity space, assuming that the volume of the
living and/or activity space is denoted as V, the gas consumption
amount inside the living and/or activity space is denoted as
B(m.sup.3/s), the gas concentration inside the living and/or
activity space at time t is denoted as .eta.(t), and the gas
concentration of the outside is denoted as .eta.0, .eta.(t) being
given as follows when air inside the living and/or activity space
is sufficiently agitated and the concentration of respective gas
molecules constituting the air is made spatially uniform:
.eta..function..eta..times..function..times..times. ##EQU00028##
eliminating entering/exiting of air as an air current between the
inside of the living and/or activity space and the outside, and at
least a part of the boundary between the living and/or activity
space and the outside being configured from a membrane not passing
through dust particles but passing through gas molecules having a
diffusion constant D, a thickness L, and an area A for gas
molecules of interest, .eta.(t) being controlled so as to vary
according to the following formula when air inside the living
and/or activity space is sufficiently agitated and the
concentration of respective gas molecules constituting the air is
made spatially uniform:
.eta..function..eta..times..function..times..times..times..times..times.
##EQU00029## further the area A of the membrane being set so as to
satisfy A.gtoreq.FL/D between F and the area A of the membrane
where F is ventilation air flow required by law or other reasons,
wherein at least one gas exchange device, the gas exchange device
having a box-like structure constituting an enclosed space with at
least two gas absorption openings and at least two gas exhaustion
openings, one of the at least two gas absorption openings
communicating with one of the at least two gas exhaustion openings
and the other one of the at least two gas absorption openings
communicating with the other one of the at least two gas exhaustion
openings, the two communicating paths being configured so that
while they form independent paths respectively, they lies adjacent
each other and they are separated by the membrane not passing
through dust particles but passing through gas molecules, air
introduced from the outside space surrounding the room being
introduced into the box-like structure of the gas exchange device
from one of the gas absorption openings and sent out to the outside
space from the gas blow opening communicating with the gas
absorption opening, while air inside the living and/or activity
space being introduced into the box-like structure of the gas
exchange device from the other one of the gas absorption openings
and returned to the living and/or activity space from the gas
exhaustion opening communicating with the gas absorption opening,
the membrane having the area not less than MAX(Amin, A'min) where
Amin is the lower limit of the area A of the membrane obtained by
the following (1) and A'min is the lower limit of the area A' of
the membrane obtained by the following (2), (1) the area A of the
membrane satisfying A.gtoreq.FL/D where A is the area of the
membrane, L is the thickness of the membrane, D is the diffusion
constant of gas molecules in the membrane and F is the ventilation
air flow required for the living and/or activity space by law or
other reasons, (2) the area A' of the membrane satisfying
'>'.times..xi..xi..times.'.times. ##EQU00030## where the area A'
of the membrane is set by scaling of {(V/A')/(D'/L)} where V is the
volume of the living and/or activity space, A' is the area of the
membrane, L is the thickness of the membrane, and D' is the
diffusion constant of carbon dioxide in the membrane, B' is the
carbon dioxide generation rate inside the living and/or activity
space, .xi.0 is the carbon dioxide concentration in equilibrium
state with the outside when no carbon dioxide is generated inside
the living and/or activity space, and .xi.(.xi.<5000 ppm) is the
target carbon dioxide concentration inside the living and/or
activity space.
4. The building according to claim 1 wherein in the gas exchange
device air inside the living and/or activity space is introduced
into the box-like structure from the other one of the gas
absorption openings and air flow f returned to the living and/or
activity space from the gas exhaustion opening communicating with
the gas absorption opening is set for F so as to satisfy
f.gtoreq.F.
5. The building according to claim 1 wherein the gas exchange
device is installed in a space between the wall constituting the
room and the living and/or activity space.
6. The building according to claim 2 wherein the medium performance
filter is made of shoji paper, non-woven fabric, synthetic fiber or
cellulose-based fiber that is folded repeatedly.
Description
TECHNICAL FIELD
The invention relates to a building, and a method for controlling
gas molecule concentration in living and/or activity space in
building. More particularly, the invention relates to a building
such as a house etc. including rooms having a space in which for
example, people do daily life and/or activity such as sleep, relax,
operation, work, etc., and a method for controlling gas molecule
concentration in such a living and/or activity space, the living
and/or activity space being preferably used as a field of, for
example, living, rest, experiment, production, painting work,
nursing activity, medical/dental treatment, etc.
BACKGROUND ART
It may be said that with respect to information processing and
communication environment, mankind realized a high convenient
environment never realized since the dawn of history with
development of computer technology at present. In other words, it
can be said that a stimulating perfect good field for brain was
realized. On the other hand, with respect to an environment for
body, it cannot be said that modern society is always a good
environment due to increase of pollution materials, floating of
dusts or infectious bacteria in air, etc.
Assume now cases where persons act inside a living space with the
oxygen consumption rate B(for example, exercise, sleep, enjoying a
one-pot dish etc. by burning an easy gas ring, etc.). With respect
to rooms in which general persons act, ventilation of a certain
amount is required by law such as the Building Standards Act etc.
This is usually achieved by introducing outside air of a certain
amount into the room. With respect to a room partitioned by shoji,
although outside air is not introduced mechanically into the room,
the room and an adjacent room as a whole are regarded as one room.
In this case, it is not always possible to say that the necessary
area of shoji etc. has been estimated quantitatively based on
modern science.
On the other hand, a clean environment exists for large-scale
semiconductor manufacture conventionally. However, the clean
environment is only for professional use, i.e., for industry. No
clean environment for consumer used for general houses has been
introduced. Once in the world of computers, personal computers
flourished, carrying the banner for "Computer for the rest of us"
and drawing the line between the personal computers and the
large-scale computer main frame for business. Like this, while the
importance of environment increases in twenty-first century, it may
be hoped that "clean environment version" of personal computers
appears. In fact, a personal clean space, which is the counterpart
of just "main frame" as large-scale clean room with the high
performance realized in long time ago, will surely become important
in the future not only for pure consumer but also for scenes such
as hospitals, institutions for the aged, etc. in which it is
important to avoid risk of infection. Particularly, it will become
more important in the future to control an air environment
including a microbial environment in a living space for the problem
of PM 2.5, pollinosis-control, further alleviation of symptoms of
asthma, prevention of bacterially caused pneumonia, etc.
Under the background, present inventors proposed a system of highly
clean rooms or a building, comprising: at least one room, the room
including a living and/or work space that is an enclosed space, the
room being provided with a fan filter unit provided with a blow
opening so as to supply gases inside the living and/or work space,
all of gases flowing inside the living and/or work space from the
blowing opening being returned to an absorption opening of the fan
filter unit, the wall of the room being provided with an opening to
exhaust gases outside the living and/or work space. In the system
of highly clean rooms or the building, by forming at least a part
of an inner surface of the room by a wall including as a part a
membrane not passing through dust particles but passing through gas
molecules(gas exchange membrane), gas molecules inside the room can
be exchanged through the membrane by concentration gradient between
the outside space surrounding the room and the internal space of
the room(see patent literatures 1-3). In this case, assuming that
the volume of the living and/or work space is V, the diffusion
constant of oxygen in the membrane included in the wall is D, and
the thickness of the membrane is L, the room is designed by scaling
the volume V and the area A of the membrane of {(V/A)/(D/L)}.
Assuming that the oxygen consumption rate is B, the volume of
oxygen inside the living and/or work space when it is in
equilibrium with the outer space and oxygen is not consumed inside
it is Vo2, and the target oxygen concentration inside the living
and/or work space is .eta.(.eta.>0.18), the area A of the
membrane is set so as to satisfy
.gtoreq..function..eta. ##EQU00002## According to the system of
highly clean rooms or the building, it is possible to realize a
daily living space itself as a clean space of, for example, class
100 or higher looking like just a common room in appearance without
decreasing its volume ratio. Furthermore, it is possible to keep
the oxygen concentration inside the living and/or work space to the
level required by law.
PRIOR ART LITERATURE
Patent Literature LITERATURE
PATENT LITERATURE 1: U.S. Pat. No. 5,329,720 PATENT LITERATURE 2:
U.S. Pat. No. 5,839,426 PATENT LITERATURE 3: U.S. Pat. No.
5,839,429
SUMMARY OF INVENTION SUBJECTS TO BE SOLVED BY INVENTION
However, according to further research by the present inventors, it
was found out that the area A necessary for the gas exchange
membrane may be not always enough for gas exchange of carbon
dioxide depending on the structure etc. inside the room. This is
because the number of digits less than a decimal point of partial
pressure of target gas to be controlled is different depending on
kind of gas. Therefore, it is required to keep the concentration of
carbon dioxide etc. inside the room to the level required by law or
other reasons. However, no concrete proposal has been made
heretofore.
On the other hand, there is a type of an air conditioner that is
installed on the ceiling, while another type of a wall-mounted air
conditioner that is installed on the wall of the room is frequently
used.
Therefore, a subject to be solved by the invention is to provide a
building that can realize a daily living and/or activity space
itself as a clean space of class 100 or higher while matching with
the standard format of a modern architecture and keep the
concentrations of carbon dioxide etc. in addition to the oxygen
concentration to the level required by law and other reasons based
on a new concept of ventilation by utilizing fully the air
circulation performance of a wall-mounted air conditioner etc. and
is suitably used for, for example, schools etc. in foreign
countries in which air environment is not always good as well as
hospitals, public facilities and general homes in Japan, and a
prefilter that is suitably attached to an absorption opening of the
wall-mounted air conditioner of rooms of the building.
The above subjects and other subjects will be apparent from the
following statement of this description referring to accompanying
drawings.
Means for Solving the Subjects
In order to solve the above subject, according to the invention,
there is provided a building comprising:
at least one room; and
at least one gas exchange device,
the room having inside a living and/or activity space that is an
enclosed space,
a wall-mounted air conditioner being installed on the wall of the
living and/or activity space, a prefilter made of a medium
performance filter being attached to an air absorption opening of
the top of the air conditioner, and all of gases flowing inside the
living and/or activity space from a blow opening of the air
conditioner being returned to the air absorption opening of the
prefilter,
the gas exchange device having a box-like structure constituting an
enclosed space with at least two gas absorption openings and at
least two gas exhaustion openings,
one of the at least two gas absorption openings communicating with
one of the at least two gas exhaustion openings and the other one
of the at least two gas absorption openings communicating with the
other one of the at least two gas exhaustion openings,
the two communicating paths being configured so that while they
form independent paths respectively, they lies adjacent each other
and they are separated by a membrane not passing through dust
particles but passing through gas molecules,
air introduced from the outside space surrounding the room being
introduced into the box-like structure of the gas exchange device
from one of the gas absorption openings and sent out to the outside
space from the gas blow opening communicating with the gas
absorption opening, while air inside the living and/or activity
space being introduced into the box-like structure of the gas
exchange device from the other one of the gas absorption openings
and returned to the living and/or activity space from the gas
exhaustion opening communicating with the gas absorption
opening,
the membrane having the area A' set by scaling of {(V/A')/(D'/L)}
where V is the volume of the living and/or activity space, A' is
the area of the membrane, L is the thickness of the membrane, and
D' is the diffusion constant of carbon dioxide in the membrane,
the area A' of the membrane being set so as to satisfy
'>'.times..xi..xi..times.' ##EQU00003## where B' is the carbon
dioxide generation rate inside the living and/or activity space,
.xi.0 is the carbon dioxide concentration in equilibrium state with
the outside when no carbon dioxide is generated inside the living
and/or activity space, and .xi.(.xi.<5000 ppm) is the target
carbon dioxide concentration inside the living and/or activity
space.
Furthermore, according to the invention, there is provided a
building comprising:
at least one room; and
at least one gas exchange device,
the room having inside a living and/or activity space that is an
enclosed space,
a wall-mounted air conditioner being installed on the wall of the
living and/or activity space, a prefilter made of a medium
performance filter being attached to an air absorption opening of
the top of the air conditioner, and all of gases flowing inside the
living and/or activity space from a blow opening of the air
conditioner being returned to the air absorption opening of the
prefilter,
the gas exchange device having a box-like structure constituting an
enclosed space with at least two gas absorption openings and at
least two gas exhaustion openings,
one of the at least two gas absorption openings communicating with
one of the at least two gas exhaustion openings and the other one
of the at least two gas absorption openings communicating with the
other one of the at least two gas exhaustion openings,
the two communicating paths being configured so that while they
form independent paths respectively, they lies adjacent each other
and they are separated by a membrane not passing through dust
particles but passing through gas molecules,
air introduced from the outside space surrounding the room being
introduced into the box-like structure of the gas exchange device
from one of the gas absorption openings and sent out to the outside
space from the gas blow opening communicating the gas absorption
opening, while air inside the living and/or activity space being
introduced into the box-like structure of the gas exchange device
from the other one of the gas absorption openings and returned to
the living and/or activity space from the gas exhaustion opening
communicating with the gas absorption opening,
the membrane having the area not less than MAX(Amin, A'min) where
Amin is the lower limit of the area A of the membrane obtained by
the following (1) and A'min is the lower limit of the area A' of
the membrane obtained by the following (2).
(1) the area A of the membrane satisfying A.gtoreq.FL/D where A is
the area of the membrane, L is the thickness of the membrane, D is
the diffusion constant of gas molecules in the membrane and F is
the ventilation air flow required for the living and/or activity
space by law or other reasons. (2) the area A' of the membrane
satisfying
'>'.times..xi..xi..times.' ##EQU00004## where the area A' of the
membrane is set by scaling of {(V/A')/(D'/L)} where V is the volume
of the living and/or activity space, A' is the area of the
membrane, L is the thickness of the membrane, and D' is the
diffusion constant of carbon dioxide in the membrane, B' is the
carbon dioxide generation rate inside the living and/or activity
space, .xi.0 is the carbon dioxide concentration in equilibrium
state with the outside when no carbon dioxide is generated in the
living and/or activity space, and .xi.(.xi.<5000 ppm) is the
target carbon dioxide concentration inside the living and/or
activity space.
Here, the lower limit Amin of the area A of the membrane equals to
the right side of A.gtoreq.FL/D and the lower limit A'min of the
area A' of the membrane is the minimum value satisfying the formula
(18). MAX(Amin, A'min) means the bigger one of Amin and A'min.
In the invention of the building, the gas exchange device is
preferably configured so that air inside the living and/or activity
space is introduced into the box-like structure from the other one
of the gas absorption openings and an air flow f that is returned
to the living and/or activity space from the gas exhaustion opening
communicating with the gas absorption opening is set for F so as to
satisfy f.gtoreq.F.
Furthermore, according to the invention, there is provided a
prefilter to be attached to an air absorption opening of the top of
a wall-mounted air conditioner of a building, comprising:
a medium performance filter,
the building comprising:
at least one room; and
at least one gas exchange device,
the room having inside a living and/or activity space that is an
enclosed space,
a wall-mounted air conditioner being installed on the wall of the
living and/or activity space,
the gas exchange device having a box-like structure constituting an
enclosed space with at least two gas absorption openings and at
least two gas exhaustion openings,
one of the at least two gas absorption openings communicating with
one of the at least two gas exhaustion openings and the other one
of the at least two gas absorption openings communicating with the
other one of the at least two gas exhaustion openings,
the two communicating paths being configured so that while they
form independent paths respectively, they lies adjacent each other
and they are separated by a membrane not passing through dust
particles but passing through gas molecules,
air introduced from the outside space surrounding the room being
introduced into the box-like structure of the gas exchange device
from one of the gas absorption openings and sent out to the outside
space from the gas blow opening communicating with the gas
absorption opening, while air inside the living and/or activity
space being introduced into the box-like structure of the gas
exchange device from the other one of the gas absorption openings
and returned to the living and/or activity space from the gas
exhaustion opening communicating with the gas absorption
opening,
the membrane having the area A' set by scaling of {(V/A')/(D'/L)}
where V is the volume of the living and/or activity space, A' is
the area of the membrane, L is the thickness of the membrane, and
D' is the diffusion constant of carbon dioxide in the membrane, the
area A' of the membrane being set so as to satisfy
'>'.times..xi..xi..times.' ##EQU00005## where B' is the carbon
dioxide generation rate inside the living and/or activity space,
.xi.0 is the carbon dioxide concentration in equilibrium state with
the outside when no carbon dioxide is generated in the living
and/or activity space, and .xi.(.xi.<5000 ppm) is the target
carbon dioxide concentration inside the living and/or activity
space,
the prefilter being configured so that when the prefilter is
attached to the air absorption opening of the air conditioner, all
of gases flowing inside the living and/or activity space from the
blow opening of the air conditioner is returned to the air
absorption opening of the prefilter.
Here, the gas exchange device in each invention mentioned above is
preferably installed in a space between the wall constituting the
room and the living and/or activity space, more particularly, for
example, a space between the roof and the ceiling or the inside of
the double wall formed on the sidewall of the room, however not
limited to this and it may be installed in a place selected as
necessary.
The room is constituted of an enclosure constituting an enclosed
space and its concrete example is a room of a building etc. The
building may be all rooms supporting human activity such as, for
example, detached houses, apartments, condominiums, hospitals,
movie theaters, nursing institutions, schools, preschools,
kindergartens, gyms, factories, paint rooms, lacquer rooms, etc.
The room can be also applied to, for example, a room inside a
mobile body with an internal space. The mobile body may be, for
example, cars, especially ambulances, planes, passenger trains,
passenger buses, sailboats, passenger boats, etc.
In the building, there is no entering/exiting of air as an air
current between the inside of the living and/or activity space and
the outside. However, since at least a part of the boundary between
the living and/or activity space and the outside is separated by
the membrane, the building has the refresh performance of inside
gases, which is equivalent to direct entering/exiting of gases
between the inside of the living and/or activity space and the
outside. Here, no entering/exiting of air as an air current means,
for example, that the incoming and outgoing air currents for the
living and/or activity space are strictly zero during operation of
the building. However, its meaning is not limited to this and it
includes, for example, entering/exiting of a clean air current with
the flow rate much smaller than the flow rate of air subjected to
100% circulation feedback in the living and/or activity space.
Furthermore, no net air current between the inside of the living
and/or activity space and the outside includes, for example, that
pressure inside and outside of the room are the same.
The living and/or activity space is a space in which people do
daily life or activity such as sleep, relax, work, labor, etc., and
is preferably used as a field of living, rest, experiment,
production, painting work, nursing activity, medical/dental
treatment, etc.
The membrane not passing through dust particles but passing through
gas molecules (gas exchange membrane) is not essentially limited as
far as it does not pass through dust particles but pass through gas
molecules between spaces separated by the membrane. For example,
the membrane not passing through dust particles but passing through
gas molecules can preferably exchange gas molecules through the
membrane when the pressure difference between spaces separated by
the membrane is zero but there is a difference of partial pressure
of gas constituents constituting air on both sides of the membrane.
Here, "not passing through dust particles" includes not only the
case where dust particles cannot pass through completely (100%) but
also the case where dust particles cannot pass through not strictly
100% (hereafter the same). Concretely, the membrane is, for
example, shoji paper from ancient times that is used generally,
medium performance filter, HEPA filter, ULPA filter, etc. More
specifically, although the blocking rate (passing rate) of dust
particles is not 100% (0%), the blocking rate of particles having a
particle diameter of 10 .mu.m or more is not less than 90% (not
larger than 10%), preferably not larger than 99% (1%). Material of
the membrane not passing through dust particles but passing through
gas molecules is selected as necessary. For example, filter
materials of a dust filter, shoji paper, nonwoven fabric, synthetic
fibers such as polyester, acryl, etc., cellulose fibers such as
pulp, rayon, etc. can be used.
The medium performance filter used for the prefilter is not limited
particularly, and for example, its collection efficiency for
particles having the particle diameter of 10 .mu.m or more is not
less than 60% and not larger than 98%. The medium performance
filter preferably has a shape in which planar filter material such
as shoji paper etc. is repeatedly folded, i.e., a shape obtained by
folding the planar filter material as valley-shape and mountain
shape, though it is not limited to the shape.
Described now is a method of deriving the inequality A.gtoreq.FL/D
and the formula (18) in the invention.
Considered now is a living and/or activity space (a space in which
persons live or act) having the volume V. Suppose that ventilation
of air flow F is performed according to the Building Standards Act
etc. It may be considered that air inside the space is sufficiently
and quickly agitated and gas molecules constituting air inside the
space become sufficiently and quickly uniform and here the
dependency on space coordinates can be ignored inside the room.
Suppose that activity using the oxygen consumption rate
B(m.sup.3/s) is performed in the room. Supposing that the oxygen
concentration inside the room at time t is .eta.(t) and the oxygen
concentration of the outside (=the oxygen concentration when oxygen
is not consumed inside the room) is .eta.0, the volume of oxygen
V.eta.(t+.delta.t) at time t+.delta.t can be expressed by using the
volume of oxygen V.eta.(t) at time t as follows.
V.eta.(t+.delta.t)=V.eta.(t)-B.delta.t+.eta..sub.0F.delta.t-.eta.(t)F.del-
ta.t (1)
The second term of the formula (1) indicates the decrease of the
volume of oxygen due to oxygen consumption during time interval(t,
t+.delta.t), the third term indicates the increase of the volume of
oxygen due to introduction of fresh air (having the oxygen
concentration .eta.0) of the outside through ventilation of air
flow F during the time interval and the fourth term indicates the
decrease of the volume of oxygen due to exhaustion of inside air
(note that its oxygen concentration is .eta.(t)) of the same amount
(with supply of outside air of the above air flow F). By
transposing the first term of the right side to the left side and
thereafter dividing the both sides by .delta.t, a differential
equation:
.times..times..times..eta..function..eta..eta..function..times.
##EQU00006## is obtained. As the initial condition, the oxygen
concentration inside the room is equal to that of the outside space
at t=0, so .eta.(0)=.eta.0 is satisfied. Therefore, the solution to
the differential equation (2) is obtained as follows.
.eta..function..eta..times..function..times..times. ##EQU00007##
When enough time has passed, the system reaches to the steady state
and the exponential function part of the formula (3) becomes zero
or the left side of the formula (2) becomes zero. Therefore, the
inside oxygen concentration converges to the constant value
.eta..eta. ##EQU00008##
On the other hand, when the living and/or activity space having the
volume V is established as an isolated system that does not
enter/exit an air current with the outside, an air current crossing
"the boundary with the outside space" that defines the living
and/or activity space as an enclosed space becomes zero. That is,
the air flow flowing into the above room (=the air flow flowing
from the room) F is zero. Instead of this, a partition is formed in
a part of the boundary by using a membrane having gas exchange
performance. The area of the membrane is denoted as A, the
thickness is denoted as L and the diffusion constant of gas
molecules passing through the membrane is denoted as D. Suppose
that oxygen is consumed at B (m.sup.3/s) per unit time as the same
as the above in the room forming an isolated enclosed space.
Avogadro number is denoted as N0, the volume of gases per 1 mol at
the pressure of the system (.about.1 atm) is denoted as C, the area
of the partition(gas exchange membrane) is denoted as A and the
flux of oxygen introduced into the enclosure through the partition
is denoted as j. Then the volume of oxygen at time t+.delta.t,
V.eta.(t+.delta.t) is expressed using the volume of oxygen at time
t, V.eta.(t) as follows.
.times..times..eta..function..delta..times..times..times..times..eta..fun-
ction..times..times..delta..times..times..times..times..times..times..delt-
a..times..times. ##EQU00009## Here, it was assumed that the
dependency on space coordinates can be ignored inside the living
and/or activity space with good approximation (as described later,
when a 100% circulation feedback system is constructed inside the
room, air inside the living and/or activity space can be
sufficiently and quickly agitated by an air current generated by
the air conditioner and gas molecules constituting air can be made
uniform sufficiently and quickly inside the living and/or activity
space).
The third term of the right side of the formula (5) is the number
of oxygen molecules flowing due to the difference of the oxygen
concentration (concentration gradient) of both sides of the gas
exchange membrane(i.e., between the inside of the living and/or
activity space and the outside) (here oxygen is introduced into the
living and/or activity space not as air current but by diffusion of
molecules and its nature is totally different from the phenomenon
described by the formulas (1).about.(4) described above). j in the
formula (5) is given as follows. j=D.gradient..PHI. (6)
Here, .phi. denotes the number of oxygen molecules per unit volume
inside the living and/or activity space and D denotes the diffusion
constant of oxygen in the gas exchange membrane. When the direction
perpendicular to the gas exchange membrane is set to be x axis,
.gradient. is the differential operator in the x axis. Assume that
the volume of the living and/or activity space is V and the
thickness of the gas exchange membrane is L. L is smaller than size
of the living and/or activity space by about three digit and the
gas exchange membrane can be regarded very thin. Therefore, the
formula (5) can be approximated with good approximation as
follows.
.times..times..eta..function..delta..times..times..times..times..eta..fun-
ction..times..times..delta..times..times..times..eta..eta..function..times-
..delta..times..times. ##EQU00010## Here, .eta.0 is the oxygen
concentration of the outside as the same as the formula (1) and the
formula (2) and usually about 20.9%. From the formula (7), the
differential equation is derived as follows.
.times..times..times..eta..function..times..eta..eta..function.
##EQU00011## The exact solution to the formula (8) can be obtained
as follows.
.eta..function..eta..times..function..times..times..times..times..times.
##EQU00012## Here, it is interesting to see the solution
corresponding to the stationary state after enough time has passed.
Therefore, by setting the left side of the formula (8)=0, the
oxygen concentration at time t can be obtained as follows(the
oxygen concentration is the same as that of the case where
t.fwdarw..infin. in the formula (9)). .eta.=.eta..sub.0-BL/AD
(10)
Compared here are the method that secures the oxygen concentration
inside the room by performing ventilation of the air flow F
according to the Building Standards Act etc. and the case where the
membrane having function of the gas exchange membrane such as shoji
paper etc. is used for a part of the living and/or activity space
to supply oxygen inside the room(within the enclosure) from the
outside (by utilizing the phenomenon that oxygen diffuses in the
gas exchange membrane in a direction in which the concentration
gradient decreases). That is, comparing the formula (2) and the
formula (8) (or the formula (4) and the formula (8)), F=AD/L (11)
is obtained. As a result, it is shown that the method that secures
the oxygen concentration inside the room by performing ventilation
of the air flow F according to the Building Standards Act etc. and
the usage of the gas exchange membrane such as shoji paper etc.
having the area A, the thickness L and the diffusion constant D of
molecules in a part of the boundary between the room and the
outside are equivalent. This is because that nitrogen in air is
basically bystander for activitity to maintain life. It is easy to
understand from analogy that while the conventional ventilation of
nonzero air flow corresponds to "whole blood donation", the method
of this invention corresponds to "blood component donation".
Effectiveness of shoji from ancient time of Japan can be understood
now strictly and quantitatively. From dimension analysis, while the
air flow F has dimension of [m.sup.3/s], AD/L has dimension of
[(m.sup.2m.sup.3/s)/m]=[m.sup.3/s], just dimension of the air flow
and therefore equivalency of both is supported. That is, the method
of securing the oxygen concentration inside the room by performing
ventilation of the air flow F according to the Building Standards
Act etc. can secure the same oxygen exchange ability by using the
gas exchange membrane having A, D, L satisfying the formula (11) in
the boundary between the airtight living and/or activity space and
the outside. The boundary may be a single gas exchange
membrane(referred as GEM, as necessary) or a unit, i.e., a gas
exchange box(referred as G.times.B, as necessary) in which many gas
exchange membranes are integrated and inside air and outside air
flow as laminar flow in both sides of each gas exchange membrane.
With this, it is possible to obtain the gas exchange
membrane(having the quantitative area constituting a part of the
enclosed space) capable of supplying necessary gas components(for
example, oxygen) inside the airtight living and/or activity space
from the outside, or exhausting unnecessary gas components(for
example, carbon dioxide) to the outside from the inside of the
enclosed space not by ventilation based on the mechanical driving
force but through diffusion occurred in a place where the
concentration gradient exists. Since law of equipartition of energy
holds, diffusion constants of each gas molecule in the gas exchange
membrane only depend on the squared root(the inverse of this) of
the mass of each molecule. Therefore, for example, diffusion
constants of carbon dioxide and oxygen have the same digit but
their precoefficients are slightly different each other(both
diffusion constants are on the order of .about.10.sup.-5
m.sup.2/s).
Considered now is consumption of oxygen and generation of carbon
dioxide when burning occurs inside the living and/or activity
space. When carbon is burned simply, C+O.sub.2=CO.sub.2 holds and
when glucose burns, finally
C.sub.6H.sub.12O.sub.6+6O.sub.2=6CO.sub.2+6H.sub.2O holds.
Therefore, the ratio of consumption of oxygen and generation of
carbon dioxide is about 1:1. Change of the carbon dioxide
concentration .xi.(t) with burning of carbon compounds directs
toward increase of the concentration with burning. Therefore, when
the inside concentration increases, carbon dioxide is emitted to
the outside. Accordingly,
.times..times..xi..function..delta..times..times..times..times..xi..funct-
ion.'.times..delta..times..times.'.times.'.times..xi..function..xi..times.-
.delta..times..times. ##EQU00013## holds where B'(m.sup.3/s) is the
carbon dioxide generation rate, .xi.0 is the carbon oxide
concentration of the outside, A' is the area of the gas exchange
membrane and D' is the diffusion constant of carbon dioxide in the
gas exchange membrane. From this,
.times..times..times..xi..function.''.times.'.times..xi..function..xi.
##EQU00014## is obtained. When the carbon dioxide concentration is
in equilibrium state between the inside and the outside at time
t=0, .xi.(0)=.xi.0. Therefore, the solution to the formula is as
follows.
.xi..function..xi.'.times.'.times.'.times..function.'.times.'.times..time-
s..times..times..times. ##EQU00015## After enough time has passed,
the carbon dioxide concentration converses to
.xi..xi.'.times.'.times.' ##EQU00016## When the inside carbon
dioxide concentration is the value C0 larger than the formula (15)
at time t=0, the solution to the formula (13) is as follows.
.xi..function..xi.'.times.'.times.'.times..function.'.times.'.times..time-
s..times..times..times..xi.'.times.'.times.' ##EQU00017##
Suppose now that the carbon dioxide concentration inside the living
and/or activity space is first in equilibrium state with the
outside space and persons act inside the living and/or activity
space. The carbon dioxide concentration inside the living and/or
activity space is required by law not to exceed a certain value
Amax. Therefore, it is necessary to set the target carbon dioxide
concentration .xi.(.xi.<.xi.max) from the formula (15) as
follows.
.xi.'.times.'.times.'<.xi..ltoreq..xi. ##EQU00018## If the area
A' of the gas exchange membrane is set as follows so as to satisfy
the formula (17), the carbon dioxide concentration inside the
living and/or activity space does not exceed the value required by
law and safety of persons who act inside the living and/or activity
space is ensured.
'>'.times..xi..xi..times.'.times. ##EQU00019##
Suppose that the target carbon dioxide concentration is set to be
.xi.(.xi..ltoreq..xi.max is satisfied). When persons act to a
certain extent inside the living and/or activity space, they act
not to exceed the target carbon dioxide .xi.. Obtained from the
formula (18) is a guiding principle that the smaller the generation
amount of carbon dioxide is, the thinner the gas exchange membrane
is and the larger the diffusion constant of carbon dioxide molecule
is, the smaller the necessary area A is. The formula (18) is
transformed as follows.
.times..times.''.times..times..ltoreq..xi..xi..times.'.function.
##EQU00020## The numerator of the left side is determined only by
the shape of the living and/or activity space (the aspect ratio of
the living and/or activity space), while the denominator of the
left side is determined by the property of the gas exchange
membrane. The left side, i.e., the ratio of the numerator and the
denominator that are distinctly distinguished determines time
constant of the response. It is understood from the formula (19)
that the larger the carbon dioxide generation rate is, the response
time must be small (i.e., prompt response is necessary). With
respect to the left side of the formula (19), any combination of
(V, A', D', L) giving the same value has the same response time as
the living and/or activity space although each value of V, A', D',
L is different. According to the scaling rule, it is possible to
design the highly clean system for any living and/or activity
space.
There are some standards that give the carbon dioxide concentration
to be obeyed. For example, according to the management standard of
environment and hygiene of building the carbon dioxide
concentration is desired to be not higher than 1000 ppm, while
according to the standard of environment and hygiene of school the
carbon dioxide concentration is desired to be not higher than 1500
ppm. However, it has been reported that the carbon dioxide
concentration of real rooms of school may reach 2500 ppm.about.3000
ppm depending on the situation(it is pointed out that although life
is not in danger, pupils may become absent-minded or concentration
of pupils becomes weak). Hygienic limit value is 5000 ppm. With
respect to oxygen, the concentration is required to be preferably
between 20 and 30% for the standard concentration of 20.9%, while
the value of 18.5% is given as the value that does not cause
problems concerning health and activity. Therefore, it is
understood from arrangement of concentration variables in the
inequality (18) that when the area of the gas exchange membrane is
determined so as to satisfy the above standard concentration, the
area necessary to obey the carbon dioxide concentration is larger
by about one digit than the area necessary to obey the oxygen
concentration. Therefore, in order to enhance gas exchange ability,
especially in exhaustion of carbon dioxide to the outside from the
inside of the room, it is effective to use the stacking structure
of many gas exchange membranes shown in FIG. 3.about.FIG. 6
described later as a core and to set so that gas components of air
inside the room (inside air) and outside air can be exchanged by
diffusion by the concentration gradient through the gas exchange
membrane while preventing direct mixing of an air current.
Diffusion constants of oxygen and carbon dioxide in air are about
1.7.times.10.sup.-5 m.sup.2/s and about 1.6.times.10.sup.-5
m.sup.2/s, respectively. It is not practical to make the
concentration of the living and/or activity space having size of
order of several meters constant by only diffusion because it takes
dozens of hours. In order to perform gas exchange efficiently and
thereafter make uniform the gas concentration inside the living
and/or activity space promptly, it is preferable to attach two fans
to the gas exchange device and produce the flow of outside air and
the flow of inside air returned to the inside of the room after gas
exchange intentionally. Flow rate is generally set to be
0.1.about.several hundred m.sup.3/min depending on size of the
living and/or activity space. The interval (width) between the gas
exchange membranes on both sides of the space in which inside air
flows and the interval (width) between the gas exchange membranes
on both sides of the space in which outside air flows are selected
as necessary. For example, the interval between the gas exchange
membranes of the space in which inside air flows can be adjusted to
be small so as to shorten time necessary for gas exchange and the
interval between the gas exchange membranes of the space in which
outside air flows can be set to be larger than that. According to
such an asymmetric establishment of the intervals of the gas
exchange membranes, it is hoped that concentration of components
after gas exchange can be locally brought close to the
concentration of outside air through the volume ratio. When the
flow rate of the fans is sufficiently large, symmetric
establishment of the interval of the gas exchange membranes is
convincing for symmetry and stability of the system as a whole
because the fans can be set symmetrically for inside air and
outside air.
From the above description, it is apparent that following
inventions of building and method for controlling gas molecule
concentration in living and/or activity space in building can be
derived. That is, according to the invention, there is provided a
building comprising:
at least one room,
the room having inside a living and/or activity space that is an
enclosed space,
if performing ventilation of an air flow F from the outside to the
living and/or activity space,
assuming that the volume of the living and/or activity space is
denoted as V, the gas consumption amount inside the living and/or
activity space is denoted as B(m.sup.3/s), the gas concentration
inside the living and/or activity space at time t is denoted as
.eta.(t), and the gas concentration of the outside is denoted as
.eta.0, .eta.(t) being given as follows when air inside the living
and/or activity space is sufficiently agitated and the
concentration of respective gas molecules constituting the air is
made spatially uniform:
.eta..function..eta..times..function..times..times.
##EQU00021##
eliminating entering/exiting of air as an air current between the
inside of the living and/or activity space and the outside, and at
least a part of the boundary between the living and/or activity
space and the outside being configured from a membrane not passing
through dust particles but passing through gas molecules having the
diffusion constant D, the thickness L, and the area A for gas
molecules of interest, .eta.(t) being controlled so as to vary
according to the following formula when air inside the living
and/or activity space is sufficiently agitated and the
concentration of respective gas molecules constituting the air is
made spatially uniform:
.eta..function..eta..times..function..times..times..times..times..times.
##EQU00022##
further the area A of the membrane being set so as to satisfy
A.gtoreq.FL/D between F and the area A of the membrane where F is
ventilation air flow required by law or other reasons.
Furthermore, according to the invention, there is provided a method
for controlling gas molecule concentration in living and/or
activity space in building,
the building comprising at least one room,
the room having inside a living and/or activity space that is an
enclosed space,
if performing ventilation of an air flow F from the outside to the
living and/or activity space,
assuming that the volume of the living and/or activity space is
denoted as V, the gas consumption amount inside the living and/or
activity space is denoted as B(m.sup.3/s), the gas concentration
inside the living and/or activity space at time t is denoted as
.eta.(t), and the gas concentration of the outside is denoted as
.eta.0, .eta.(t) being given as follows when air inside the living
and/or activity space is sufficiently agitated and the
concentration of respective gas molecules constituting the air is
made spatially uniform:
.eta..function..eta..times..function..times..times.
##EQU00023##
eliminating entering/exiting of air as an air current between the
inside of the living and/or activity space and the outside, and at
least a part of the boundary between the living and/or activity
space and the outside being configured from a membrane not passing
through dust particles but passing through gas molecules having the
diffusion constant D, the thickness L, and the area A for gas
molecules of interest, .eta.(t) being controlled so as to vary
according to the following formula when air inside the living
and/or activity space is sufficiently agitated and the
concentration of respective gas molecules constituting the air is
made spatially uniform:
.eta..function..eta..times..function..times..times..times..times..times.
##EQU00024##
further the area A of the membrane being set so as to satisfy
A.gtoreq.FL/D between F and the area A of the membrane where F is
ventilation air flow required by law or other reasons, thereby
keeping the quality of air inside the living and/or activity space
well while eliminating entering/exiting of air as an air current
between the inside of the living and/or activity space and the
outside.
In the inventions, typically, with respect to the gas molecules of
interest, the gas molecules are exchanged between the inside of the
living and/or activity space and the outside only when there exists
difference in their concentration between the inside of the living
and/or activity space and the outside, or further, when air
environment inside the living and/or activity space is controlled,
gas molecules other than the gas molecules of interest that exist
outside the living and/or activity space are not exchanged.
Effect of the Invention
According to the invention, it is possible to obtain the same
effect as a case where ventilation of flow rate F is performed
effectively through diffusion of gas molecules without exchanging
gases between the inside of the living and/or activity space and
the outside (although the flow rate of exchange of an air current
between the inside and the outside F=0). That is, it is possible to
give quantitatively the area of the gas exchange membrane necessary
to obey at least the concentration of gases that is determined by
law or the concentration of gases that is determined by other
reasons. In addition to this, by using the 100% circulation
feedback system using the air circulation performance of the air
conditioner, it is possible to realize a gas environment inside the
highly clean room while securing sure and safety of
persons(operators, pupils applying themselves to their studies,
etc.) who act inside the room.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 A cross sectional view showing a building according to the
first embodiment.
FIG. 2 A perspective view showing an air conditioner installed on
the wall of the living etc. space of a room of the building
according to the first embodiment and a prefilter attached to an
air absorption opening of the air conditioner.
FIG. 3 A top view showing an example of the box-like structure of
the gas exchange device that is used in the building according to
the first embodiment.
FIG. 4 A front view showing the example of the box-like structure
of the gas exchange device that is used in the building according
to the first embodiment.
FIG. 5 A side view showing the example of the box-like structure of
the gas exchange device that is used in the building according to
the first embodiment.
FIG. 6 A cross sectional view along 6-6 line of FIG. 3.
FIG. 7A A front view showing an example of the gas exchange device
that is used in the building according to the first embodiment.
FIG. 7B A side view showing the example of the gas exchange device
that is used in the building according to the first embodiment.
FIG. 8 A cross sectional view showing a building according to the
second embodiment.
FIG. 9 A perspective view showing two walls crossing each other of
the living etc. space of the room of the building according to the
second embodiment seen from the inside of the living etc.
space.
FIG. 10 A perspective view showing the state where the gas exchange
device 300 is installed in a space behind one wall of the living
etc. space of the room of the building according to the second
embodiment.
FIG. 11 A perspective view showing two walls crossing each other of
the living etc. space of the room of the building according to the
second embodiment seen from the inside of the living etc.
space.
FIG. 12A A front view showing an example of the gas exchange device
that is used in the building according to the second
embodiment.
FIG. 12B A left side view showing the example of the gas exchange
device that is used in the building according to the second
embodiment.
FIG. 12C A right side view showing the example of the gas exchange
device that is used in the building according to the second
embodiment.
FIG. 13A A substitute picture for a drawing taken of mainly the
side of a gas exchange part of the gas exchange device that was
made in the example 1.
FIG. 13B A substitute picture for a drawing taken of the top of the
gas exchange part of the gas exchange device that was made in the
example 1.
FIG. 13C A substitute picture for a drawing taken of the top and
the side of the gas exchange part of the gas exchange device that
was made in the example 1.
FIG. 13D A substitute picture for a drawing taken of the side of
the gas exchange part of the gas exchange device that was made in
the example 1.
FIG. 13E A substitute picture for a drawing taken of the side of
the gas exchange device that was made in the example 1.
FIG. 14 A substitute picture for a drawing showing the gas exchange
device that was made in the example 2.
FIG. 15 A substitute picture for a drawing showing a living etc.
space of a room of a building according to the example 2.
FIG. 16 A substitute picture for a drawing showing the state where
the gas exchange device shown in FIG. 14 is installed in a space
behind one shoji of the living etc. space shown in FIG. 15.
FIG. 17A A schematic diagram showing the result of measurement of a
change over time of the oxygen concentration when a gas ring was
burned in the room in the example 2.
FIG. 17B A schematic diagram showing the result of measurement of a
change over time of the carbon dioxide concentration when the gas
ring was burned in the room in the example 2.
FIG. 18 A substitute picture for a drawing showing a prefilter that
was made in the example 3.
FIG. 19 A substitute picture for a drawing showing the state where
the prefilter that was made in the example 3 was attached to an air
absorption opening of an air conditioner installed on the wall of a
conventional general room.
FIG. 20 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles when a
conventional general room was cleaned using the air conditioner
installed on the wall of the room and the prefilter that was
attached to the air absorption opening of the air conditioner.
FIG. 21 A schematic diagram showing the result of demonstration of
the lifetime of a medium performance filter that is used for the
prefilter.
FIG. 22 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles when the air
conditioner was operated setting the flow rate to be low in the
example 3.
FIG. 23 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles according to
their particle diameters when the air conditioner was operated
setting the flow rate to be low in the example 3.
FIG. 24 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles when the air
conditioner was operated setting the flow rate to be medium in the
example 3.
FIG. 25 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles according to
their particle diameters when the air conditioner was operated
setting the flow rate to be medium in the example 3.
FIG. 26 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles when the air
conditioner was operated setting the flow rate to be high in the
example 3.
FIG. 27 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles according to
their diameters when the air conditioner was operated setting the
flow rate to be high in the example 3.
FIG. 28 A substitute picture for a drawing showing the state where
the prefilter shown in FIG. 18 was attached to the air absorption
opening of the air conditioner installed on the wall of a
conventional general room in the example 4.
FIG. 29 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles when the air
conditioner was operated in the example 4.
FIG. 30 A substitute picture for a drawing showing the state where
a commercially available medium performance filter as the prefilter
was attached to the air absorption opening of the air conditioner
installed on the wall of a conventional general room in the example
5.
FIG. 31 A substitute picture for a drawing showing the commercially
available medium performance filter that was used in the example
5.
FIG. 32 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles when the air
conditioner was operated in the example 5.
FIG. 33 A substitute picture for a drawing showing the state where
a commercially available medium performance filter as the prefilter
was attached to the air absorption opening of the air conditioner
installed on the wall of a conventional general room in the example
6.
FIG. 34 A substitute picture for a drawing showing the commercially
available medium performance filter that was used in the example
6.
FIG. 35 A schematic diagram showing the result of measurement of a
change over time of the density of dust particles when the air
conditioner was operated in the example 6.
MODES FOR CARRYING OUT THE INVENTION
Modes for carrying out the invention (hereafter referred as
"embodiments") will now be explained below.
1. The First Embodiment
FIG. 1 shows a building according to the first embodiment. Although
the building has generally a plularity of rooms, only one room is
shown in FIG. 1. As shown in FIG. 1, the building has a room 100
with high airtightness except for an air supply opening 10 and an
air exhaustion opening 20. The room 100 forms an enclosed space.
The shape of the room 100 is determined as necessary. The shape of
the room 100 is, for example, a rectangular parallelepiped shape
with a rectangular planar shape, a shape with a planar shape of a
concave hexagonal shape(or L-shape) that is obtained by truncating
one corner rectangular region of the rectangular planar shape, a
shape with a U-shape planar shape, a shape in which all or a part
of walls of these rooms is curved, etc. The room 100 has a living
and/or activity space(hereafter referred as "living etc. space")
101 and a space 102 between the roof and the ceiling as subspaces
constituting the enclosed space. The space 102 between the roof and
the ceiling is an internal space formed by the double ceiling. The
double ceiling is constituted by the top surface 103 of the room
100 and a ceiling wall 104 formed so as to face the top surface 103
a constant distance apart. That is, the living etc. space 101 and
the space 102 between the roof and the ceiling are separated by the
ceiling wall 104. The living etc. space 101 is a space in which one
or more persons lives, works, has a meeting, etc. therein and has
the necessary size. The room has a window or a door for going in
and out of persons, though their illustration and description are
omitted.
A wall-mounted air conditioner 200 is installed on the wall of a
sidewall 106 of the living etc. space 101. A rectangular
parallelepiped prefilter 250 made of a medium performance filter is
attached to an air absorption opening of the top of the air
conditioner 200. FIG. 2 shows a perspective view of the air
conditioner 200 installed on the wall and the prefilter 250
thereon. The prefilter 250 is made of filter material 250b such as
shoji paper etc. put in a box 250 a with open base and top, the
filter material 250b being folded repeatedly to form mountain-shape
and valley-shape. Shown in FIG. 2 as an example is a case where the
inside of the box 250 a is divided into four spaces by partition
boards 250c and the filter material 250b such as shoji paper etc.
that form mountain-shape and valley-shape is put in each space with
the same direction, but not limited to this, and form and placing
method of the filter material 250b may be selected as necessary.
Preferably, a mesh-like cover is attached to the top of the
prefilter 250 so as to prevent large dusts falling on the filter
material 250b. In the cover, openings are formed with the size,
number and arrangement so as not to reduce ventilation conductance
too much. Air inside the living etc. space 101 is absorbed into the
inside of the prefilter 250 from the top of the prefilter 250, then
air that is filtered and cleaned by the filter material 250b enters
into the inside of the air conditioner 200 from the air absorption
opening, and is finally blown out into the inside of the living
etc. space 101 from a ventilation opening of the lower part of the
air conditioner 200. In this case, in the inside of the living etc.
space 101, all of air sent out from the ventilation opening of the
air conditioner 200 is returned to the top of the prefilter 250.
That is, the 100% circulation feedback system is constituted.
On the other hand, a gas exchange device 300 is installed on the
ceiling wall 104. Openings 104c, 104d are formed in parts of the
ceiling wall 104 corresponding to an inside air collection opening
301 and a return opening 302, respectively. An outside air
introduction opening 303 of the gas exchange device 300 is
connected to an air supply opening 10 formed in a sidewall 105 of
the room 100, if necessary through a duct. An exhaustion opening
304 of the gas exchange device 300 is connected to an air
exhaustion opening 20 formed in the sidewall 106, if necessary
through a duct. The inside air collection opening 301 of the gas
exchange device 300 is connected to the opening 104c formed in the
ceiling wall 104, if necessary through a duct. The return opening
302 of the gas exchange device 300 is connected to the opening 104d
formed in the ceiling wall 104, if necessary through a duct. At
least one gas exchange membrane 310 is enclosed in the gas exchange
part inside the gas exchange device 300. Air inside the living etc.
space 101 is introduced into one space of the gas exchange part
separated by the gas exchange membrane 310 through the opening 104c
formed in the ceiling wall 104 and the inside air collection
opening 301 of the gas exchange device 300 and outside air is
introduced into the other space of the gas exchange part separated
by the gas exchange membrane 310 through the air supply opening 10
formed in the sidewall 105 and the outside air introduction opening
303 of the gas exchange device 300. And oxygen in the outside air
is introduced into the one space through the gas exchange membrane
310 and carbon dioxide in the inside air introduced into the one
space is introduced into the other space through the gas exchange
membrane 310 in the direction opposite to that of oxygen. In this
way, the inside air supplied with oxygen from the outside air is
returned to the living etc. space 101 from the return opening 302
of the gas exchange device 300. The outside air supplied with
carbon dioxide from the inside air is exhausted outside from the
exhaustion opening 304 of the gas exchange device 300 and the air
exhaustion opening 20 formed in the sidewall 106.
The gas exchange device 300 is concretely constituted, for example,
as follows. FIG. 3.about.FIG. 6 show an example of the structure of
the gas exchange part 350 inside the gas exchange device 300. Here,
FIG. 3.about.FIG. 6 are top view, front view, side view and cross
sectional view along 6-6 line of FIG. 3 of the gas exchange part
350, respectively. FIG. 7A and FIG. 7B are front view and side view
of the gas exchange device 300, respectively.
As shown in FIG. 3.about.FIG. 6, the gas exchange part 350 is
constituted as follows. That is, the gas exchange membrane 310 is
put up on two spacers S1 with height of h1 having a rectangular
cross section formed on one plane of a square flat board 351 along
two sides opposite to each other. Stacked on the gas exchange
membrane 310 are spacers S2 with height of h2 having a rectangular
cross section formed on parts corresponding to two sides opposite
to each other lying at right angles to the spacers S1, on which the
gas exchange membrane 310 is put up. Stacked on the gas exchange
membrane 310 are spacers S1 on which the gas exchange membrane 310
is put up. Similarly, the spacers S2 on which the gas exchange
membrane 310 is put up and the spacers S1 on which the gas exchange
membrane 310 is put up are stacked alternately and repeatedly. On
the last spacers S1 on which the gas exchange membrane 310 is put
up, two spacers S2 with height of h2 having a rectangular cross
section formed on one plane of a flat board 352 of the same shape
as the flat board 351 along two sides opposite to each other are
formed, laying the spacers S2 down. In this example, a total of 19
sheets of the gas exchange membrane 310 is formed. The total area
of the gas exchange membrane 310 included in the gas exchange part
350 is determined so as to satisfy the formula (18) or
A.gtoreq.FL/D, or determined to be not less than MAX(Amin, A'min).
Since the gas exchange membrane 310 is very thin, if its thickness
is ignored, the interval between the two gas exchange membranes 310
separated by the spacers S2 is about h2 and the interval between
the two gas exchange membranes 310 separated by the spacers S1 is
about h1. The space between the two gas exchange membranes 310
separated by the spacers S2 is a space for passing inside air and
the space between two gas exchange membranes 310 separated by the
spacers S1 is a space for passing outside air. The direction along
which outside air flows and the direction along which inside air
flows lie each other nearly at right angles. h1, h2 are selected as
necessary. In order to perform exchange of carbon dioxide in inside
air and oxygen in outside air efficiently through the gas exchange
membranes 310, it is desired that the introduction amount of
outside air is set to be larger than the introduction amount of
inside air relatively. Therefore, generally, it is determined to be
h1.gtoreq.h2, preferably h1>h2. In the gas exchange part 350
shown in FIG. 3.about.FIG. 6, a case of h1>h2 is shown. More
specifically,
it is selected to be, for example, h1.apprxeq.(2.about.7).times.h2.
For example, h1=25 mm, h2=5 mm. When h1 and h2 are different each
other, it is preferable to set the shape of the gas exchange part
350 of FIG. 4 to be a rectangle in which the aspect ratio is set in
the direction so as to equalize ventilation conductances of outside
air and inside air according to the ratio of h1 and h2.
As shown in FIG. 7A and FIG. 7B, the gas exchange device 300 has an
enclosure 360, which main body has a shape like a dodecahedron.
Both sides of the enclosure 360 spread in one direction from the
base and the upper base of the dodecahedron and forms a nonagon in
which one side passing on one mountain ridge 361 of the enclosure
360 is sufficiently longer than other sides. Formed on long sides
passing the mountain ridges 361 of both sides of the enclosure 360
are thin long support parts 362, 363 projecting perpendicularly to
the both sides and elongating along the long sides of the enclosure
360. When the gas exchange device 300 is fixed, it is fixed to the
installation place by threading bolts through holes (not
illustrated) formed in a plurality of places of the support parts
362, 363. The box-like gas exchange part 350 is enclosed in the
enclosure 360. The flat boards 351, 352 on the both sides of the
gas exchange part 350 are almost in contact with the both sides of
the enclosure 360 and mountain ridges 351.about.354 on the corner
of the gas exchange part 350 match the mountain ridges 361,
364.about.366 of the enclosure 360, respectively. Therefore, the
gas exchange part 350 is enclosed in the enclosure 360 so that the
gas exchange part 350 hardly moves. When the gas exchange device
300 is fixed, the gas exchange membrane 310 is vertical. Therefore,
even though dusts enter the space between the two gas exchange
membranes 310 facing each other, they fall naturally. As a result,
it is possible to prevent the gas exchange performance from
lowering due to generation of clogging up by piling up of dusts on
the surface of the gas exchange membrane 310.
Cylindrical outside air introduction opening 303, return opening
304, exhaustion opening 304 and inside air collection opening 301
are formed on four sides 367.about.370 of the enclosure 360,
respectively. In this case, outside air introduced from the outside
air introduction opening 303 passes through the space between the
two gas exchange membranes 310 separated by the spacers S1 and then
exhausted from the exhaustion opening 304. Inside air introduced
from the inside air collection opening 301 passes through the space
between the two gas exchange membranes 310 separated by the spacers
S2 and then exhausted from the return opening 302.
According to the first embodiment, since the total area A' of the
gas exchange membranes 310 included in the gas exchange part 350 is
determined so as to satisfy the formula (18), it is possible to
keep the carbon dioxide concentration as well as the oxygen
concentration at a level required by law or other reasons. In
addition to this, although the room 100 is an general room in which
the wall-mounted air conditioner 200 is installed on the wall, it
is possible to make the living etc. space 101 a clean space with
cleanliness not less than, for example, class 100by the 100%
circulation feedback system by only attaching the prefilter 250
that is the medium performance filter to the gas absorption opening
of the air conditioner 200. Furthermore, since the prefilter 250 is
the medium performance filter, its clogging up is hard to occur
after it is used for a long time. Therefore, the lifetime of the
prefilter 250 is very long, so that it is possible to lower
frequency of exchange of it remarkably. The building is preferably
used for, for example, schools in foreign countries in which air
environment is hard to say well as well as hospitals, public
facilities and general homes in Japan.
2. The Second Embodiment
FIG. 8 shows a building according to the second embodiment. As the
same as the first embodiment, only one room is shown in FIG. 8. As
shown in FIG. 8, the building has the room 100 with high
airtightness except for the air supply opening 10 and the air
exhaustion opening 20. As the same as the first embodiment, the
wall-mounted air conditioner 200 is installed on the sidewall 105
of the living etc. space 101 and the rectangular parallelepiped
prefilter 250 made of the medium performance filter is attached to
the air absorption opening of the top of the air conditioner 200.
FIG. 9 shows a perspective view of two walls 101a, 101b crossing
each other seen from the inside of the living etc. space 101. As
shown in FIG. 9, shojis 401, 402 are attached to the walls 101a,
101b. The gas exchange membrane 310 is used as shoji paper of the
shojis 401, 402. The gas exchange device 300 is installed in a
space behind the shoji 401, not on the ceiling wall 104, which is
different from the first embodiment. FIG. 10 shows a state where
one side half of the shoji 401 is opened and FIG. 11 shows a state
where the shoji 401 is shut. As shown in FIG. 10, the gas exchange
device 300 is installed on a stand 500 in a space enclosed by the
ceiling wall 104, the sidewall 106 of the room 100, the shoji 401
and the stand 500.
The gas exchange device 300 is concretely constituted, for example,
as shown in FIG. 12A, FIG. 12B and FIG. 12C. Here, FIG. 12A, FIG.
12B and FIG. 12C are front view, left side view and right side view
of the gas exchange device 300, respectively. As shown in FIG. 12A,
FIG. 12B and FIG. 12C, the gas exchange device 300 has the regular
quadratic prism enclosure 360. The gas exchange part 350 shown in
FIG. 3.about.FIG. 6 is enclosed inside the enclosure 360 in a state
where the gas exchange part 350 is rotated by 45.degree. for the
enclosure 360. More specifically, the gas exchange part 350 is
enclosed inside the enclosure 360 in a state where four mountain
ridges of the gas exchange part 350 is inscribed with bisectors of
each side of the enclosure 360. The cylindrical outside air
introduction opening 303 and return opening 302 are formed in one
side of the enclosure 360, respectively and the cylindrical
exhaustion opening 304 and inside air collection opening 301 are
formed in another side facing the one side.
As shown in FIG. 10, the gas exchange device 300 is fixed to two
support parts 501, 502 that are fixed to a stand 500 by L-shape
metal fittings (not illustrated), laying its one side in which the
inside air collection opening 301, the return opening 302, the
outside air introduction opening 303 and the exhaustion opening 304
are not formed down. Each one end of ducts 601, 602, 603, 604 is
connected to the inside air collection opening 301, the return
opening 302, the outside air introduction opening 303 and the
exhaustion opening 304 of the gas exchange device 300,
respectively. The other end of the ducts 601, 602, 603, 604
elongates upward to thread the ceiling wall 104, and further passes
through the space 102 between the roof and the ceiling and is
connected to the opening 104c formed in the ceiling wall 104, the
opening 104d formed in the ceiling wall 104, the air supply opening
10 formed in the sidewall 105 and the air exhaustion opening 20
formed in the sidewall 106, respectively. When the gas exchange
device 300 is fixed, the gas exchange membrane 310 is vertical.
Therefore, even though dusts enter the space between the two gas
exchange membranes 310 facing each other, they fall naturally. As a
result, it is possible to prevent the gas exchange performance from
lowering due to generation of clogging up by piling up of dusts on
the surface of the gas exchange membrane 310.
Outside air can be introduced through a duct not illustrated into a
space behind the shoji 401 in which the gas exchange device 300 is
installed. Therefore, gas exchange can be performed between the
space in which the gas exchange device 300 is installed and the
living etc. space 101 by using the shoji paper itself of the shoji
401 as the gas exchange membrane 310. Though not illustrated, a
similar space is formed behind the shoji 402 and outside air can be
introduced into the space through a duct not illustrated. These
spaces are separated each other.
Construction of the building other than the above is the same as
the first embodiment.
According to the second embodiment, it is possible to obtain the
same advantages as the first embodiment.
EXAMPLES
Example 1
In the example 1, described is an example of the gas exchange
device 300, which was actually made, used in the building according
to the first embodiment.
FIG. 13A, FIG. 13B, FIG. 13C, FIG. 13D and FIG. 13E are pictures
showing the gas exchange device 300. Here, FIG. 13A, FIG. 13B, FIG.
13C, FIG. 13D and FIG. 13E are a picture taken of mainly the side
of the gas exchange part of the gas exchange device 300, a picture
taken of the top of the gas exchange part, a picture taken of the
top and the side of the gas exchange part(FIG. 13C and FIG. 13D)
and a picture taken of the side of the gas exchange device 300. The
enclosure 368 is made of iron and the flat boards 351, 352 and the
spacers S1, S2 are made of wood. The intervals h1, h2 of the gas
exchange membrane 310 of the gas exchange part 350 of the gas
exchange device 300 are set to be h1=25 mm, h2=5 mm. That is, the
interval of the gas exchange membranes 310 of both planes of the
passage through which outside air flows and the interval of the gas
exchange membranes 310 of both planes of the passage through which
inside air flows are asymmetrically set. Size of the gas exchange
part 350 is 60 cm.times.60 cm.times.30 cm, size of the gas exchange
membrane 310 is 58 cm.times.58 cm and number of the gas exchange
membrane 310 is 19 as the same as the example shown in FIG.
3.about.FIG. 6. The total area of the gas exchange membrane 310 of
the gas exchange device 300 (G.times.B) is about 6.4 m.sup.2.
Example 2
The example 2 corresponds to the second embodiment.
FIG. 14 is a picture showing the gas exchange device 300 that was
made in the example 2. Here, in FIG. 14, the front board of the gas
exchange device 300 is removed and therefore the gas exchange part
350 inside the gas exchange device 300 can be seen. The flat boards
351, 352 and the spacers S1, S2 are made of wood. The intervals h1,
h2 of the gas exchange membrane 310 of the gas exchange part 350 of
the gas exchange device 300 are set to be h1=h2=10 mm. That is, the
interval of the gas exchange membranes 310 of both planes of the
passage through which outside air flows and the interval of the gas
exchange membranes 310 of both planes of the passage through which
inside air flows are symmetrically set. Size of the gas exchange
part 350 is 31 cm.times.31 cm.times.30 cm, size of the gas exchange
membrane 310 is 30 cm.times.30 cm and number of the gas exchange
membrane 310 is 29. The total area of the gas exchange membrane 310
of the gas exchange device 300 (G.times.B) is about 2.6 m.sup.2.
Here, a fan filter unit installed on the ceiling wall 104 of the
living etc. space 101 is used instead of the wall-mounted air
conditioner. A pair of openings is formed in parts of the ceiling
wall 104 corresponding to an air absorption opening and an air blow
opening of the fan filter unit, respectively. And air inside the
living etc. space 101 is absorbed from the opening formed in the
part of the ceiling wall 104 corresponding to the air absorption
opening of the fan filter unit, then air enters into the air
absorption opening of the fan filter unit and finally all of air
cleaned by the fan filter unit is blown inside the living etc.
space 101. Flow rate of the fan filter unit is set to be about 20
m.sup.3/min. The volume of the living etc. space 101 of the room
100 is about 70 m.sup.3. The area of the gas exchange membrane 310
of the shojis 401, 402 is about 3.3 m.sup.2.
FIG. 15 is a picture of the living etc. space 101 used in the
embodiment 2 taken from the inside of the living etc. space 101.
Size of the living etc. space 101 is about 17 mats. FIG. 16 is a
picture showing the state where the gas exchange device 300 shown
in FIG. 14 is installed in the space behind one shoji 401 of the
living etc. space 101 shown in FIG. 15.
FIG. 17A and FIG. 17B show the result of measurement of a change of
the oxygen concentration and the carbon dioxide concentration,
respectively when a desktop gas ring was burned in the living etc.
space 101. In the living etc. space 101 in which there is no
exchange of an air current between the inside and the outside(F=0
in the above discussion), a cassette gas ring of butane was burned
all the way to increase the carbon dioxide concentration once. FIG.
17B shows the change of the carbon dioxide concentration after the
gas exchange device 300 was operated thereafter. The oxygen
concentration was measured by using Oxyman Plus OM-25MP01 (Taiei
engineering) and the carbon dioxide concentration was measured by
using datalogger MC-383SD(SATOTECH). Combustion of butane is
described as follows.
C.sub.4H.sub.10+6.5O.sub.2=4CO.sub.2+5H.sub.2O From this, it may be
considered to be B'.about.0.6 B. When oxygen decreases by
combustion from 20.9% to 19.9% by about 0.01 (i.e. 10000 ppm), it
is predicted that carbon dioxide increases from the formula (20) as
follows. 10000 ppm.times.4/6.5.about.6200 ppm (20)
Actually, when oxygen decreased to 19.8% at time 12:30 in FIG. 17A
and FIG. 17B, carbon dioxide increased to about 6800 ppm from the
initial value of about 400 ppm. This result coincides with the one
predicted by the formula (20). Since definite symmetrical change
over time can be seen for the oxygen concentration and the carbon
dioxide concentration in FIG. 17A, it is understood that time
constants of change of both concentrations and therefore the
diffusion constants of oxygen and carbon dioxide in the gas
exchange membrane 310 are nearly equal. The gas exchange membrane
310 (GEM2) (its area is about 3.3 m.sup.2) of the shoji 402 on the
right of FIG. 9 was operated till time 11:45 and the gas exchange
membrane 310 (GEM1) (its area is about 3.3 m.sup.2) of the shoji
401 on the left of FIG. 9 was also operated from time 11:15. First
cylinder of butane gas fuel was dead at time 11:45. Therefore,
second cylinder of butane gas fuel was used and the gas ring was
burned all the way. Since the cylinder of butane gas fuel was full,
the carbon dioxide concentration increased immediately. It was
found that the cylinder butane gas fuel became empty (butane of 250
g was burned out) in about 80 minutes in this combustion condition.
According to calculation based on the formula (2) from the
combustion amount of fuel per unit time, this corresponds to the
consumption amount of oxygen of about 31 persons. Although the
number of persons is too much to be accommodated in the living etc.
space 101 of the room 100 shown in FIG. 8, the oxygen concentration
was kept to be 19.8%, which is not smaller than 18.5% (one standard
of safety). When the gas exchange device 300 (G.times.B)(the total
area is about 2.6 m.sup.2) was operated at time 12:30, the oxygen
concentration turned to decreasing(this behavior is definitely
described by the formula (16)). It was shown that the gas exchange
device 300 in which the flow speed of gases near the gas exchange
membrane 310 is large is more favorable than the gas exchange
membrane 310. Although the carbon dioxide concentration became
about 4800 ppm, which is below the hygiene limit value, it is very
rare that 31 persons enter the living etc. space 101 of 17 mats.
However, this suggests that it is not preferable for such many
persons to stay in the room for a long time. If the number of
persons is limited to several persons(4 persons for obeying the
management standard of environment and hygiene of building and 8
persons for obeying the standard of environment and hygiene of
school), it is understood that it is possible to stay in the living
etc. space 101 of the room 100 equipped with the 100% circulation
feedback system using the shojis 401, 402 and the gas exchange
device 300 for a long time peacefully and safely(although
ventilation amount by exchange of bulk air mass between the inside
and the outside of the room is zero). Butane gas fuel was exchanged
by third cylinder of butane gas fuel at time 13:10. However,
decreasing tendency of carbon dioxide continued. From this, effect
of the gas exchange device 300 can be confirmed. Comparing FIG. 17A
and FIG. 17B, it is understood that it is possible to stop lowering
of the oxygen concentration in the living etc. space 101 by
operating the 100% circulation feedback system using the gas
exchange membrane 310 and the gas exchange device 300 in the living
etc. space 101 and prevent the carbon dioxide concentration from
increasing at the same time. It was demonstrated that gas exchange
was performed efficiently.
Example 3
As shown in FIG. 18, the prefilter 250 was made. In the prefilter
250, a box with a width of about 20 cm and a length of about 80 cm
was divided into four spaces by partition boards and filter
material folded like mountain-shape and valley-shape are enclosed
in respective spaces. Here, ASAHIPEN shoji paper No. 5641 was used
as filter materials for easy working. FIG. 19 shows an example in
which the prefilter shown in FIG. 18 was attached to the air
absorption opening of the top of the usual wall-mounted air
conditioner installed on the wall of a conventional general room in
which the density of dust particles is high. As the air
conditioner, RAS-KJ22B(W) made by Hitachi, Ltd. was used. A tape
was used to seal up the top of the air conditioner and the
prefilter.
FIG. 20 shows the result of measurement of a change over time of
the density of dust particles in the room when the air conditioner
200 in which the prefilter 250 was attached to the air absorption
opening was operated in the room shown in FIG. 19. As shown in FIG.
20, cleanliness of the room was US 209D class a hundred and twenty
thousand and there were many dusts before the air conditioner 200
with the prefilter 250 was operated, while after operation of the
air conditioner 200 the density of dust particles began to decrease
rapidly and the density of dust particles decreased to US 209D
class 4000, which is about one-thirtieth after 10 hours passed.
That is, although the collection efficiency .gamma. of the medium
performance filter used for the prefilter 250 is never high, high
cleanliness could be attained according to the formula (5)
described above. By selecting materials of the prefilter 250 so
that the collection efficiency .gamma. is nearer to 1 and the
pressure loss is low and large flow rate can be obtained, it is
possible to realize remarkably high cleanliness more shortly
according to the formula (5).
Described now is the result of estimation of the lifetime of the
medium performance filter used as the prefilter 250. A tent-like
structure in which all of planes forming the structure are made of
the gas exchange membrane was made. The tent-like structure was
disposed on the floor of a bedroom of an apartment and a subject
slept on a futon spread on the floor. A fan filter unit and a dust
counter(a particle counter) were disposed on the floor inside the
tent. An air cleaner made by Panasonic Corporation (F-PDH35) was
used as the fan filter unit. The air cleaner uses a medium
performance filter with .gamma.=98%. While the inside of the tent
was cleaned by operating the air cleaner continuously, the subject
slept in usual living rhythm. After the air cleaner was operated
for about four years, the density of dust particles inside the tent
was measured by the dust counter during sleep. FIG. 21 shows the
result. As shown in FIG. 21, the operation characteristic of the
air cleaner was not degraded after the air cleaner was continuously
used for about four years. This is because clogging up of the
medium performance filter is difficult to occur.
Described now is the result of experiment investigating a change
over time of the density of dust particles in the room shown in
FIG. 19 when the air conditioner 200 with the prefilter 250
attached to the air absorption opening was operated in the room
while its flow rate was changed at three levels, that is, low flow
rate, medium flow rate and high flow rate, and decrease of the
number of particles according to their particle diameters at each
flow rate. The change over time of the density of dust particles in
the room when the air conditioner 200 was operated at low flow
rate, medium flow rate and high flow rate is shown in FIG. 22, FIG.
24 and FIG. 26, respectively. Decrease of the number of dust
particles according to their particle diameters when the air
conditioner 200 was operated at low flow rate, medium flow rate and
high flow rate is shown in FIG. 23, FIG. 25 and FIG. 27,
respectively. From FIG. 22, FIG. 24 and FIG. 26, it is understood
that the total of the number of dust particles of particle diameter
of 0.5 .mu.m or more decreases with time irrespective of flow rate.
Furthermore, from FIG. 23, FIG. 25 and FIG. 27, it is understood
that since shoji paper (ASAHIPEN shoji paper No. 5641) was used as
the filter materials of the prefilter 250, particles of particle
diameter of 10 .mu.m or more can be well collected, while the
collection efficiency .gamma. tends to decrease according to
decrease of particle diameter. It is also understood that since air
inside the room is filtered by passing through the prefilter 250
repeatedly by the air circulation performance of the air
conditioner 200, collection of particles of particle diameter not
larger than 10 .mu.m proceeds gradually with time.
Example 4
FIG. 28 shows an example in which the prefilter shown in FIG. 18
was attached to the air absorption opening of the top of the usual
wall-mounted air conditioner installed on the wall of the
conventional general room in which the density of dust particles is
high. Here, S25TTES-W made by DAIKIN INDUSTRIES, LTD was used as
the air conditioner. A tape was used to seal up the top of the air
conditioner and the prefilter.
FIG. 29 shows the result of measurement of a change over time of
the density of dust particles in the room when the air conditioner
200 with the prefilter 250 attached to the air absorption opening
was operated in the room. As shown in FIG. 29, cleanliness of the
room was US 209D class a hundred thousand and there were many dusts
before the air conditioner 200 with the prefilter 250 was operated,
while after operation of the air conditioner 200 the density of
dust particles began to decrease rapidly and the density of dust
particles decreased to US 209D class 4000, which is about 1/25
after 4 hours passed.
Example 5
FIG. 30 shows an example in which a commercial medium performance
filter was attached as the prefilter 250 to the air absorption
opening of the top of the usual wall-mounted air conditioner
installed on the wall of the conventional general room in which the
density of dust particles is high. Here, S25TTES-W made by DAIKIN
INDUSTRIES, LTD was used as the air conditioner. A tape was used to
seal up the top of the air conditioner and the prefilter. FIG. 31
shows a picture taken of the commercial medium performance filter
used as the prefilter 250 (dust collection filter KAFPO44A4 made by
DAIKIN INDUSTRIES, LTD).
FIG. 32 shows the result of measurement of a change over time of
the density of dust particles in the room when the air conditioner
200 with the prefilter 250 attached to the air absorption opening
was operated in the room. As shown in FIG. 32, cleanliness of the
room was US 209D class a hundred thousand and there were many dusts
before the air conditioner 200 with the prefilter 250 was operated,
while after operation of the air conditioner 200 the density of
dust particles began to decrease rapidly and the density of dust
particles decreased to US 209D class 1000, which is about 1/10
after 50 minutes passed.
Example 6
FIG. 33 shows an example in which a commercial medium performance
filter was attached as the prefilter 250 to the air absorption
opening of the top of the usual wall-mounted air conditioner
installed on the wall of the conventional general room in which the
density of dust particles is high. Here, S25TTES-W made by DAIKIN
INDUSTRIES, LTD was used as the air conditioner. A tape was used to
seal up the top of the air conditioner and the prefilter. FIG. 34
shows a picture taken of the commercial medium performance filter
used as the prefilter 250 (filter for exchange for the air cleaner
FZ-Z51HF made by SHARP CORPORATION).
FIG. 35 shows the result of measurement of a change over time of
the density of dust particles in the room when the air conditioner
200 with the prefilter 250 attached to the air absorption opening
was operated in the room. As shown in FIG. 35, cleanliness of the
room was US 209D class thirty thousand and there were many dusts
before the air conditioner 200 with the prefilter 250 was operated,
while after operation of the air conditioner 200 the density of
dust particles began to decrease rapidly and the density of dust
particles decreased to US 209D class 300, which is about 1/100
after 1 hour passed.
Heretofore, embodiments and examples of the invention have been
described specifically. However, the invention is not limited to
these embodiments and examples, but contemplates various changes
and modifications based on the technical idea of the invention.
For example, oxygen and carbon dioxide are exemplified as gas
molecules in the embodiments. However, it is possible to apply to
carbon monoxide CO, hydrogen sulfide H2S, etc. other than these
according to nature of region such as a hot spring region etc. or
according to situations such as a one-pot dish cooked at the table
using a charcoal briquette(if .xi.,.xi.0used for carbon dioxide are
defined again for gas species of interest, the above formula and
formula transformation can be applied. Of course, .xi.0.about.0 for
CO, H2S in the usual living etc. space 101). Furthermore, numerical
numbers, structures, constitutions, shapes, materials, etc.
presented in the above embodiments and examples are only examples,
and the different numerical numbers, structures, constitutions,
shapes, materials, etc. may be used as necessary.
EXPLANATION OF REFERENCE NUMERALS
10 . . . air supply opening, 20 . . . air exhaustion opening, 100 .
. . room, 101 . . . living etc. space, 103 . . . roof, 104 . . .
ceiling wall, 104a, 104b, 104c, 104d . . . opening, 105, 106 . . .
sidewall, 200 . . . air conditioner, 250 . . . prefilter, 250a . .
. box, 250b . . . partition board, 250c . . . filter material, 300
. . . gas exchange device, 301 . . . inside air collection opening,
302 . . . return opening, 303 . . . outside air introduction
opening, 304 . . . exhaustion opening, 310 . . . gas exchange
membrane, 350 . . . gas exchange part, 360 . . . enclosure, 401,
402 . . . shoji
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